Yeah I was with my dad and he painted his oil pan with the stuff (gloss black). It wasn't raining but it was plenty humid. When he finished it looked beautiful. It had a great shine. A few minutes later we looked again and it was gray. We didn't understand so he piled some more color on it and it predictably did the same thing. I think at that point I started reading the label and figured it out.Yeah the ball peen hammer trick is one i was taught years back....definitely makes it easier. Funny you mentioned the gloss black engine enamel turning gray....happened to me and i couldn't figure out why at first. Duh, jackass me, pouring rain and trying to spray ceramic paint.